What are atoms?
Atoms are the building blocks of a matter.A single atom is the smallest particle of a chemical element that still has all the features and properties of that particular element . But are not the tiniest particle of all.They are made up of even smaller pieces , called sub atomic particles.
Sub atomic particles
There are three sub atomic particles namely electrons,neutrons and protons.In every chemical element each kind of the particle is the same .
Inside atom
An atom has a central part called nucleus.This contain sub atomic particles named protons and neutrons.Each proton has a electrical charge , almost like a tiny electrical battery -only positive charge.Neutrons are the same size of protons but the don't have electrical charge.Electrons are much smaller than protons and neutrons.They are not in nucleus . They whiz around in layers, that layers are known as shells.Electrons are negative charged opposite to protons. Usually an atom has same numbers of protons and electrons.So the negative and positive charges are equal , which means the whole atom has no electric charge .
Discovery of an atom
During the 18 century , scientists developed their theories about atom as the smallest particle , which lasted for ever and could not be split up . But in 19 century led to the idea that atoms were not the smallest particles.By 1911 ,Ernest Rutherford had carried out experiments ,which showed that that the atoms heave even smaller particles inside it.He suggested that there was a small heavy nucleus at the center of the atom , with much smaller.lighter particles called electrons,orbiting around it .The electrons can randomly move around the nucleus. In 1913 , Neils Bohr improved this idea by suggesting that electrons had to stay at a certain distance from the nucleus , in layers called shell.And this idea is still accepted today.
Atoms are the building blocks of a matter.A single atom is the smallest particle of a chemical element that still has all the features and properties of that particular element . But are not the tiniest particle of all.They are made up of even smaller pieces , called sub atomic particles.
Sub atomic particles
There are three sub atomic particles namely electrons,neutrons and protons.In every chemical element each kind of the particle is the same .
Inside atom
An atom has a central part called nucleus.This contain sub atomic particles named protons and neutrons.Each proton has a electrical charge , almost like a tiny electrical battery -only positive charge.Neutrons are the same size of protons but the don't have electrical charge.Electrons are much smaller than protons and neutrons.They are not in nucleus . They whiz around in layers, that layers are known as shells.Electrons are negative charged opposite to protons. Usually an atom has same numbers of protons and electrons.So the negative and positive charges are equal , which means the whole atom has no electric charge . Discovery of an atom
During the 18 century , scientists developed their theories about atom as the smallest particle , which lasted for ever and could not be split up . But in 19 century led to the idea that atoms were not the smallest particles.By 1911 ,Ernest Rutherford had carried out experiments ,which showed that that the atoms heave even smaller particles inside it.He suggested that there was a small heavy nucleus at the center of the atom , with much smaller.lighter particles called electrons,orbiting around it .The electrons can randomly move around the nucleus. In 1913 , Neils Bohr improved this idea by suggesting that electrons had to stay at a certain distance from the nucleus , in layers called shell.And this idea is still accepted today.
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